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My son in law just bought an 82 Fleetwood with a 4100 engine. It started leaking oil out of the front of the crank. I assumed it was the timing cover seal but when we pulled the pulleys I noticed the balancer had no bolt and the leak was between the balancer and the crank.

I have heard on the 4100 they don't always come with a balancer bolt and the bolt hole is plugged with a cork:confused: Also the keyways on the crank come with RTV sealant on them to keep them from leaking oil.

Any info would be appretiated.
 

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The info you have is correct. a "cork" was pressed into the center holeof the vibration dampner! Also as you were told, sealant was used on the crank keyway. My thought on the leak is that it could be excess pressure in the crankcase. Check the PCV system for restriction. The hose to the PCV as well as the PCV itself. Also check the nipple were the hose attaches to the throttle body. Could be partially plugged with crud! Also ck the fresh air supply hose from the air filter housing to the valve cover. The hose connector at the valve cover, as well, could be restricted.
 

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So when replacing the timing chain / set, should the balancer bolt be purchaced to replace the cork that has been removed, or find another piece of cork??
 

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FYI: I relpaced the timing chain and gears on my '85 Seville 4100 engine and also noticed that there was no bolt in the crank to hold the pulley on. After buttoning up the job and running about 150 miles, I went back to retorque the front end bolts and found the front pulley just about ready to fall off. That would have been a small disaster!

I solved the problem by tapping the crank and fitting a bolt with a flat washer available from GM for that purpose. Needless to say, works great and some peace of mind.
 

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I replaced the timing set on my 1985 eldo 4100.. Is the balancer tapered to stay on or should I find a bolt for it? What size is the balancer bolt on a 4100?
 

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There is no bolt on the damper on the early HT4100 engines...no bolt was put on the damper on that engine until about 1988 I think when it went to the 4.5.


The cork is really just a cork pushed into the hole in the end of the crank to keep dirt and crud out of the threaded hole in the end of the crank. There IS a threaded hole in the end of the crank that is used to pull the damper on. If the damper is pulled on with the correct puller that threads into the hold in the end of the crank the damper bolt is simply not needed.

If there is oil leaking from the damper to crank interface then there must be some unusually high crankcase pressure or,more likely, the damper is loose on the crank and is not seated completely. Possibly in the last 23 years since the engine was built the damper has lost its original press load on the end of the crank and crept away from the timing drive gear slightly. There was no RTV put on the damper at the factory and no RTV used to seal the damper to the timing key.... Just the damper seated against the timing gear provided the seal...which has proven to be sufficient in just about all the HT4100 engines....except the one you have it seems.

I would STRONGLY recommend that you take the opportunity to replace the timing chain and driven gear on the camshaft as it is likely about to fail. Those were the infamous nylon toothed sprockets that were good for about 100K or ten years...whichever came first.... When you replace the timing drive pull the damper on with the correct puller and it should be fine. Besides the normal failure of the nylon teeth on the top gear on the cam the bottom gear is likely loose on the crank and only being driven by the key in the keyway on the crank. The bottom gear or sprocket was designed to be clamped by the damper when it is pressed on and if it is now loose (suspected and likely) it would be the leak source due to the clearance between the gear and the damper snout and it will have fretted severely on the key in the crank keyway. Likely the timing gear on the bottom will have the key slot fretted very wide and possibly it has even cracked. If it does crack then it will take out the timing drive and drop parts into the oil pan.....not good.

For a temporary repair I would suggest finding a large bolt that will fit the end of the crank and a large washer and tighten firmly...about 120 ftlbs. That should reseat the damper to the crank snout and the bottom timing gear and cease the oil seepage and stop any further fretting of the bottom timing gear. Then arrange a replacement of the timing drive chain and sprockets ASAP to prevent any further failure.

Possibly someone already replaced the timing drive chain and sprockets...????....I would say highly likely as I cannot believe a 1982 HT4100 is still running with the original timing drive....so the most likely scenario I can think of is that they didn't get the damper fully seated and pressed all the way onto the crank snout when they did the work. It needs to be seated to stop the oil seepage and I would still want to check the bottom sprocket for fretting if it was running like that for long.

You can go to the Cad dealer and order the crank damper bolt for a 1988 4.5 engine and it will work on the 82 I am pretty sure......tighten it securely and leave it in there. The cork was just a convenience item to keep the dirt out of the threads in the crank.... I have seen the cork still in place after hundreds of thousands of miles so if it is missing it is a futher clue that someone was in there already working on it and that is probably why there is an oil leak now due to the damper not being seated.
 
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